NPS Why is there a detour?During high water events the towpath between mile 84.4 and mile 89.1 may be covered in water. When is the detour needed?The detour is not needed all the time, only during high water events of the Potomac River - usually in the spring or fall after a heavy storm.What is the detour like?The detour follows local roads. It is approximately 6 miles long and is over narrow paved roads with no shoulders and limited sight distances. Those using the detour should do so with extreme caution and use lights and high visibility clothing.When is the towpath closed?The park monitors Potomac River levels to determine when portions of the towpath, hiking trails, or parking areas might be affected by rising river levels. By visiting the National Oceanic and Atmospheric Administration - National Weather Service Advanced Hydrologic Prediction Service, you can see a timeline of expected river rises and crests to help plan your visit to the park.When the river gauge is at 11 feet the park closes the towpath because the Potomac River will begin to overtop the towpath along low sections of Big Slackwater. When will the towpath reopen?After the flood water recede, the park will leave the gates closed to allow cleanup of the flood sections. Please avoid using this section prior to completion of cleanup. The towpath will be covered in mud and may have large trees and other debris on it making use very difficult and dangerous.Do I have to follow the detour?Avoid using the towpath during flood watches and warnings. Do not use the towpath when it is closed.Users of the towpath can become stranded as the water begins to rise. If you come to a section of the towpath covered by the water, do not cross. It may be deeper than you think. |
Last updated: July 8, 2025